A USB connector may be a type “A” connector with rectangular shape and four pints. USB type A connectors can be found on upstream devices such as a USB host or a hub. USB type A plugs can be found on cables, and smaller peripherals such as a mouse and a flash drive. However, USB devices and peripherals such as printers and scanners use the USB type “B” receptacle. A USB type b connector has a shape that is more akin to a square. FIGS. 1A and 1B illustrate examples of these connectors.
Connecting a peripheral to a host involves a USB type A to type B cable. The two types of plugs have the same number of pins, and are electrically identical. They are only different mechanically. This was an intentional feature designed by the USB specification to prevent connecting a host to another host, which could cause a short circuit.
More recently, a USB type “C” connector has been developed. FIG. 2 illustrates examples of USB types A, B, and C. While USB type A and type B connectors are unidirectional, a USB type C connector is bidirectional. type C connectors were developed with the advent of the USB Specification version 3.0 and later. Versions of the USB Specification include 1.1, 2.0, 3.0, and 3.1. USB 1.1 was released in 1998 and has a top speed of 12 Mbps. In many cases, USB 1.1 only performs at 1.2 Mbps. Released in 2000, USB 2.0 has a maximum speed of 480 Mbps in hi-Speed mode, or 12 Mbps. It is backward-compatible with USB 1.1 and has a maximum output power of 2.5 V (1.8 A). USB 3.0 was released in 2008 and has a top speed of 5 Gbps in SuperSpeed mode. It is backward-compatible with USB 2.0, and can deliver up to 5V (1.8 A) of power.
The most recent version of USB is 3.1, which was released in 2013 and doubles the speed of 10 Gbps. It is backward-compatible with USB 3.0 and USB 2.0. USB 3.1 has three power profiles and allows larger devices to draw power from the host: up to 2 A at 5 V (for a power consumption of up to 10 W), and up to 5 A at either 12V (60 W) or 20V (100 W).
With a flat and rectangular shape, the USB type-A was the original design for the first USB standard. On a traditional USB cable, the type-A connector, also known as the A-male connector goes into a host, and the USB port where the type A-male is inserted into is referred to as a type A-female port. type-A ports are typically in host devices, such as desktop computers, laptops, game consoles, keyboards, mice, thumb drives, head units, and media players. Generally, the type-B connector is the end of the standard USB cable that plugs into a peripheral device such as a printer, phone, or external hard drive, and is also known as the type B-male. The port on the device itself is referred to as the type B-female.
Since peripheral devices come in a variety of shapes and sizes, the type-B connector and its companion port also come in several different designs. Designs for the USB type-B's plugs and connectors include the original Standard-B, the Mini-B, Micro-B USB, Micro-B USB 3.0, and the Standard-B USB 3.0.